Lathe toolholder



LATHE TOOL HOLDERA Filed July 7, 1941 Patented Jan. 19, 1943 UNITED STATES PATENT OFFICE LATHE TOOLHOLDER Herbert D. Mellon, Canton, Ohio Application July 7, 1941, Serial No. 401,352

3 Claims.

The invention relates generally to lathe tool holders and more particularly to an improved holder for tapered shank twist drills and reamers and like tools used in a lathe.

In drilling a piece of work in a lathe, the work is held in a chuck on the headstock and rotated, while the drill is non-rotatively held in the tailstock and fed toward the work. In order to hold the drill in the tailstock, the tapered shank of the drill is sometimes tightly fitted directly into the tapered socket of the tailstock spindle, and the drill is held from turning by the friction between the drill shank and the socket. However, the turning action of the .work on the drill often causes some turning of the drill shank in the spindle socket and a slight amount of such turning will score the spindle socket and ruin it for further work.

Moreover, with the drill shank iitted directly in the socket of the tailstock spindle, there is no way to get the feel of the drilling action, and con-l sequently the drill is apt to be fed in too rapidly and broken.

Prior tool holder constructions have included a cylindrical body with a handle extendingradially therefrom, the body having at one end a tapered bore to t the tapered Shanks of standard drills and reamers, and having at its other end a conical depression to receive the center point of the tailstock center. Such a tool allows the operator to get the feel of the drilling action andA eliminates scoring the tailstock spindle socket, but is dangerous to use for several reasons.

For example, when the drill breaks through the inside end of the work piece, it has a tendency to pull away from the tailstock due to lack of re-w sistance and the spiral of the drill iiutes, and ac-V cordingly the conical depression of the holder pulls away from the tailstock center piece so that the drill and holder has no support other than the engagement of the drill with the work.

Also, it frequently happens that during the drilling operation, the operator accidentally unintentionally backs o the tailstock a small amount, and because of the short bearing between the tailstock center and the tool holder the slightest back movement of the tailstock removes the support from the tool holder.

In either event, the sudden load of the holder on the outer end of the drill when engaged with the rotating work piece is bound to cause damage to the work or drill or to the lathe itself, and serious injury to the operator may result, especially since the natural tendency of the operator is to grasp and try to hold the drill or holder with his hands.

It is therefore a general object of the present invention to provide a novel and improved tool holder for a lathe which renders a drilling or reaming operation entirely safe and prevents damage to the tool and lathe.

Another and more speciiic object is to provide a novel and improved tool holder which will support a drill or the like in a lathe, regardless of the drill breaking through the work piece.

Another object is to provide a novel and improved tool holder which will always support a drill or the like in a lathe, even though the tailstock is backed off during the drilling operation.

A further object is to provide a novel and improved tool holder which is safe and convenient for the most inexperienced operator to use, and which is simple and inexpensive to construct.

These and other objects are accomplished by the parts, improvements, structures and combinations comprising the present invention, which is shown in the accompanying drawing and hereinafter described and claimed.

In general terms the invention may be brieiiy described as including a tool holder having a tapered socket for receiving the drill shank, and a tapered swivel member for tting the socket of the tailstock spindle.

Referring to the drawing in which a preferred embodiment of the invention is shown by way of example,

mounting a drill therein;

Fig. 2 is a detached elevation of the improved tool holder with a drill positioned therein, parts being broken away;

Fig. 3 is a similar view with parts in section;

' and Fig. 4 is a transverse sectional View as on line 4 4, Fig. 2.

Similar numerals refer to similar parts throughout the several views of the drawing.

In Fig. 1 a part of an ordinary lathe is shown in plan elevation somewhat diagrammatically. The lathe includes ways 5, a headstock 6, tailstock 'I and a carriage 8. The carriage has a cross slide 9 thereon and a tool rest I0 is mounted thereon in a usual manner.

An ordinary lathe chuck II shown mounted in the headstock 6 and a piece of work I2 is secured in the chuck. The tail-stock is provided with the usual tailstock spindle I3 which is operated by the hand wheel I4, and which is locked in desired position by the locking lever I5. The tailstock spindle I3 is provided with :a tapered bore or socket indicated at I 6.

The parts of the lathe thus far described are conventional and well known, and form no part of the present invention.

The improved tool holder preferably includes a cylindrical body I'I which has a tapered longitudinal bore I8 opening from one end and a longitudinal spindle I9 projecting from the other end. The tapered bore I8 is adapted to t tightly the tapered Shanks Ioi? standard drills, reamers andthe like, Aand one such drill isl indicated at with its tapered shank 2| tted into the bore I8.

The body I'I of the .tool holder is provided with a transverse slot 22 extending through the hblder and communicating at one side with the inner end of the tapered bore IB, and the `ila-tt'erred end 23 provided on .the shanks of standard taper shank tools is adapted to extend into the transverse slot 22 as shown in Figs. 2 and 3, to prevent the drill from turning Ain the 4tool holder.

When it is desired to remove the drill from the holder, an ordinary drift pin is driven into the slot 22 to loosen the drill. Y

The body IIV -of the tool holder is provided with a handle'24 extending `at right angles thereto or radially therefrom to facilitate handling vthe tool holder and to prevent it from turning with the drill during the drilling operation. The spindle I9 has swiveled thereon a sleeve 25 which has a tapered exterior surface adapted to t snugly into the tapered bore or socket I6 of the tailstock spindle. A screw 25 is screwed into the end of the spindle I9 for holding the sleeve 25 on the spindle While permitting it to rotate on thespindle.

In the operation of the improved tool holder, if it is desiredto drill a hole in the work piece I2, a center is vrst spotted on the workpiece in a customaryvmanner. The desired drill 20 is then selected and its shank 2I positioned inthe socket IB of the handle, with the flattened end 23 of the shank entered into the slot 22. The holder'and the drill are then positioned 'as shown in Fig. 1, with the tapered sleeve 25 tted Vtightly in the tapered socket I6 of the tailstock spindle The handle 24 of the holder is rotated so as to rest upon the toolrest Ill, and preferably upon a block of wood 2l positioned on the tool-rest as shown in Fig. 1. By using a block under the handle 24 a -space under the end of the handle Y21| is provided in order to make yit easier for the operator to grasp the handle.

The work piece I2 is now rotated Vby rotating Vthe headstock 6 and the drill is fed toward the work piece gradually by manipulation `of the handle wheel ILl to drill a hole through the Work piece. During the drilling operation the holder is held against rotation by the abutment between `of .the drill.

the handle 24 and the block 21, and the operator can at any time grasp the handle to get the feel of the drilling action so as not to feed the drill into the work too rapidly.

The swiveled sleeve 25 provides a bearing supporting the tool holder so that even though the drill -tends to pull away from the tailstock when it breaks through the inside end of the work piece, or if the operator unintentionally backs oi the tailstock during Hthe drilling operation, there is no danger of the holder 'dropping down and imposing a sudden load on the shank end Moreover, .the swivel sleeve 25 provides a support for the drill and holder without any possibility of scoring the socket in the tailst-ock'spindle, because the spindle I9 of the holder is swiveled in the tapered sleeve.

Thus a drilling operation in a lathe can be performed by an unskilled operator without any danger Iof damage to the lathe or tool or holder, and without any danger of personal injury,

The improved to'ol holder is simple and compact in construction and extremely'easy to use.

I claim:

-1. "A toolholder'fo'ra lathe having 'a body provided `v`rith a radially projecting handle, said bdy'b'ein'g provided atone end with a tapered "socket for't'ting'the Itapered shank of a drill and lin which smttheinatterred end 'of the drnrshank is adaptedto'beengaged, la spindle on the other end of said body, an exteriorly tapered fsleeve swiveled on said spindle and adapted for -fitting into themtap'ered socket of lthe tailstock spindle of 'the lathefand a screw secured-in 4'theend of 'the-spind'lefor holdings'aid sleeve on said spindle -while permitting the sleeveftorotate.

`3. Af tool-holder for a lathe having abody-pro lvided with-a 'radially projecting handle, said body beingfprovided at 'one end 'with a tapered socket for -tting the tapered shank of a drill -and the like,"-sai'd-body havinga transverse slot communicating with 'the inner "endof said *socket lis adapted -tobe ngaged,and a tapered'supportbody-an'd adapted for fitting' in the taperedsocket 'of the tailstck spindle of the lathe.

HERBERT D. MELLO'N. 

